CONTENTS. 



Page. 



Art. XXIII.— Diversity of the Glacial Period; by T. C. 



Chamberlin 171 



XXIV. — Specific Heat of Liquid Ammonia : by C. Lude- 



king and J. E. Starr 200 



XXV. — Stratigraphic relations of the Oneonta and Chemung 

 formations in eastern Central New York; by N. H. 

 Darton 203 



XXVI.— Estimates of Geologic Time ; by W. Fpham 209 



XXVII. — Notes on the Cambrian in Missouri and the Classi- 

 fication of the Ozark Series; by A. Winslow 221 



XXVIII.— A Short Cycle in Weather; by J. P. Hall --... 227 



XXIX. — Kilauea in August, 1892; by F. S. Dodge 241 



XXX. — Address delivered before the American Metrological 

 Society, Dec. 30, 1892, by the President, Dr. B. A. 

 Gould , 246 



SCIENTIFIC INTELLIGENCE. 



Chemistry and Physics — Energy as a Dimensional unit, Ostwald, 251. — Permea- 

 bility of Precipitated Membranes, Tammann : Fluosulphonic acid, Thorpe and 

 Kirman, 252. — Carbon di-iodide, Moissan: Photographic study of the movement 

 of projectiles, F. Neesen, 253. — New Species of Magnetic and Electrical 

 Instruments, G-. Quincke : Refraction of electrical waves by alcohol, H. 0. G-. 

 Ellinger: Absorption spectra, Julius, 254. — Optical Indicatrix and the Trans- 

 mission of Light in Crystals, L. Fletcher: Text-book of Physics, largely exper- 

 imental, E. H. Hall and J. T. Bergen, Jr.: Theoretical Mechanics, J. Spencer, 

 255. 



Terrestrial Physics — Gravity Determinations at the Sandwich Islands, E. D. 

 Preston, 256. 



Obituary — Frederick Augustus Genth, 257. 



